I'm usually against the "why is this posted on HN" comments, so can someone just clue me into why they personally find this so interesting? Is it the effort put into the calculation or the revenue angle?
Which is about as jaw-dropping as what people spend on WoW and other pay-to-play games to get to the end game.
(Even more incidentally, I am pretty sure you can get to WoW's end-game within a couple of years of playing, so $150–$300 seems like a reasonable estimate of that game's TCO.)